Aspects of this disclosure relate to wireless communication systems. In particular, aspects of this disclosure relate to selecting a relay device for device-to-device communication with a target device in a partial coverage scenario.
Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks) and third-generation (3G) and fourth-generation (4G) high speed data/Internet-capable wireless services. There are presently many different types of wireless communication systems in use, including Cellular and Personal Communications Service (PCS) systems.
Examples of known cellular systems include the cellular Analog Advanced Mobile Phone System (AMPS), and digital cellular systems based on Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), the Global System for Mobile access (GSM) variation of TDMA, and newer hybrid digital communication systems using both TDMA and CDMA technologies. More recently, Long Term Evolution (LTE) has been developed as a wireless communication protocol for wireless communication of high-speed data for mobile phones and other data terminals. LTE is based on GSM, and includes contributions from various GSM-related protocols such as Enhanced Data rates for GSM Evolution (EDGE), and Universal Mobile Telecommunications System (UMTS) protocols such as High-Speed Packet Access (HSPA).
In recent years, use of device-to-device (D2D) communications has increased. Examples of D2D communications (also known as peer-to-peer (P2P) communications) include Bluetooth Low Energy (BTLE), WiFi-Direct, WiFi Aware, and LTE-Direct (LTE-D).
D2D communication protocols enable devices to discover one another and establish a D2D network. An access point can configure an interval at which devices announce themselves, allocate channel resources for D2D network communications, etc. However, when a wireless device is out of coverage, it becomes problematic to establish or maintain D2D communications with wireless devices that are in coverage. This may be referred to as a partial coverage scenario. Accordingly, solutions are needed for selecting a relay device for device-to-device communication with a target device in a partial coverage scenario.